var intToRoman = function (num) {
  let map = [[1000, "M"], [900, "CM"], [500, "D"], [400, "CD"], [100, "C"], [90, "XC"], [50, "L"], [40, "XL"], [10, "X"], [9, "IX"], [5, "V"], [4, "IV"], [1, "I"]];
  let str = ''
  for (var [value, symbol] of map) {
    while (num>=value) {
      num -= value
      str += symbol
    }
    if(num==0) break
  }
  return str
};
console.log(intToRoman(1311));
//1100
